A wide variety of gasket constructions are available for sealing in various environments, including high temperature environments. Many gasket constructions have automotive applications, as well as other more generalized applications.
One of the more popular high temperature resistant gasket constructions is the spiral wound gasket. This generally comprises an outer circumferential metal sheath and an intermediate winding of sheet material, such as an asbestos material, wound on an inner metallic sheath. Spiral wound gaskets are generally annular and define a central opening. Such a gasket is generally intended to seal against a pair of confronting flanges which define confronting openings which the gasket central opening is intended to surround. The sealing faces of the flanges act against the edges of the gasket to provide the seal. Spiral wound gaskets are expensive to fabricate. However, they may be constructed to have high temperature resistance and have relatively good recovery characteristics. As such, they are widely used in high temperature environments, and have application in some high-temperature, high pressure automotive environments.
Spiral wound gaskets do not easily lend themselves to use in automotive environments, in large measure because they do not easily or readily lend themselves to securement in gasket assemblies, or to precise positioning relative to the members to be sealed. As such, their use results in problems of maintaining alignment and overall assembly when gasket assemblies are to be juxtaposed in automotive engine environments.
Therefore, it would be of advantage to make available an improved high temperature-resistant gasket element which is readily assembleable in overall automotive gasket assemblies, to provide such a gasket element which is relatively simple to fabricate, and to provide such a gasket element which has substantially improved recovery characteristics.
A variety of gaskets have been developed to provide for increased compressibility and for improved recovery. One such patent, U.S. Pat. No. 4,397,472, discloses an improved cylinder bead gasket assembly, especially adapted to be positioned between an engine head and block, and particularly for sealing combustion cylinders in such an engine. That patent discloses the use of embossments and of flexible expanded graphite disposed in the embossments to provide enhanced combustion opening sealing. U.S. Pat. No. 4,397,472 discusses prior art embossments and fillers for gaskets, and prior art suggestions for the use of expanded graphite in high temperature, high stress applications.